1. Field of the Invention
The present invention relates to a construction of a floor panel for a platform of a truck or a battery tray of an electric vehicle or a hybrid vehicle.
2. Description of the Related Art
Conventionally, there has been known a vehicular rear deck in which at least a floor panel of the rear deck is formed of a synthetic resin; at least a pair of cross ribs extending in the vehicle width direction is provided on the lower surface of the floor panel; a concave portion is formed in the floor panel between these cross ribs; and further a bottom wall of the concave portion is provided between the ribs and is formed with an opening (for example, Unexamined Japanese Utility Model Publication No. 3-102385 (claim, Specification 19th line on page 2 through 14th line on page 2, FIGS. 2 and 3). For the rear deck of this vehicle, the concave portion is closed by a plug.
In the vehicular rear deck constructed as described above, a bolt is inserted through the opening formed in the bottom wall of the concave portion, and this bolt is further inserted through an elastic material and a chassis frame so that a nut is threadedly engaged with the bolt, by which the floor panel is assembled to the chassis frame. Therefore, the strength of a body mount portion at which stress concentrates can be secured, and also the number of parts can be decreased to reduce the manufacturing cost.
However, in the conventional vehicular rear deck described in the aforementioned Publication, the elastic material is interposed between the bottom wall of concave portion and the chassis frame. Therefore, when the bolt is inserted through these elements, there is a fear of inadvertently dropping the elastic material, which presents a problem of decreased the efficiency of work for assembling the floor panel to the chassis frame.
Also, in the conventional vehicular rear deck described in the aforementioned Publication, the opening through which the bolt is inserted is formed in the bottom wall of concave portion that is made of a synthetic resin. Therefore, if the thickness of bottom wall is small, there is a fear that a crack is formed in the bottom wall by stress concentration at the periphery of the opening, and if the thickness of bottom wall is large, there is a fear that a sink mark (depression formed in the surface at the time of molding) is produced in the bottom wall.